“What would explain all that?” He held up a hand. “Wait, I don’t want to make you say it again: you don’t know.”

“Remember when Quinn said ‘someone hacked the universe’?”

“You’re getting your ideas from Quinn now? What happened to you being a genius?”

She ignored the gibe. “The universe has certain rules. Like the operating system software for a computer. None of what we’re seeing can be happening under the software of our universe. The way Caine can move things with his mind. The way you can make light come from your hands. These aren’t just mutations: they are violations of the laws of nature. At least the laws of nature as we understand them.”

“Yeah. So?”

“So.” She shook her head ruefully, disbelieving her own words as she said them. “So I think it means…we’re not in the old universe anymore.”

Sam stared at her. “There’s only one universe.”

“The theory of multiple universes has been around for a long time,” Astrid said. “But maybe something happened that began altering the rules of the old universe. Just a little, just in a small area. But the effect spread, and at some point it became impossible for the old universe to contain this new reality. A new universe was created. A very small universe.” She took a deep breath, a relieved sound, like she’d just set down a heavy load. “But you know what, Sam? I’m smart, but I’m not exactly Stephen Hawking.”

“Like if someone installed a virus in the software of the old universe.”

“Right. It started small. Some changes in individuals. Petey. You. Caine. Kids more than adults because kids are less fully formed, they’re easier to alter. Then, on that morning, something happened that tipped the balance. Or maybe several somethings.”

“How do we get through that barrier, Astrid?”

She laid her hand over his. “Sam, I’m not sure there is a ‘through.’ When I say we’re in a different universe, I mean we may not have any point of contact with the old universe. Maybe we’re like soap bubbles that can drift together and join. But maybe we’re like soap bubbles a billion miles apart.”

“Then what’s on the other side of the barrier?”

“Nothing,” she said. “There is no other side. The barrier may be the end of all that is, here in this new universe.”

“You’re depressing me,” he said, trying and failing to make it lighthearted.

She twined her fingers through his. “I could be wrong.”

“I guess I’ll find out in…what is today? In less than a week.”

Astrid had no answer for that. They sat together and gazed out over the desert. In the distance a lone coyote trotted along, nose down to catch a scent of prey. A pair of buzzards inscribed lazy circles against the sky.

After a while Sam turned toward Astrid and found her lips waiting. It felt easy and natural. As easy and natural as something could feel that made Sam’s heart threaten to break out of his chest.

They drew apart, saying nothing. They leaned against each other, both reveling in that simple physical contact.

“You know what?” Sam said at last.

“What?”

“I can’t spend the next four days in a permanent cringe,” Sam said.

Astrid nodded, a movement he felt rather than saw.

“You make me brave, you know?” Sam said.

“I was just thinking that I don’t want you to be brave anymore,” Astrid said. “I want you to be with me. I want you to be safe and not go looking for trouble, just stay with me, stay close to me.”

“Too late,” he said with forced lightness. “If I blink out, where does that leave you and Little Pete?”

“We can take care of ourselves,” she lied.

“You’re very confusing, you know that?” Sam said.

“Well, you’re not as smart as I am, so you’re easy to confuse.”

He grinned. Then grew serious again. He stroked her hair with one hand. “The thing is, Astrid, I can spend the time being afraid, trying to find a way to escape. Or I can spend the time standing up. Maybe then, if I do disappear, maybe at least you and Little Pete…”

“We could all just—” she began.

“Nah. We couldn’t. We couldn’t just hide out in the woods eating dehydrated camping food. We can’t just hide.”

Astrid’s lip trembled and she brushed at a tear just forming.

“We have to go back. At least, I do. I have to stand up.”

As if to illustrate the point, Sam stood up. He took Astrid’s hand and drew her after him. Together they walked back to the others.

“Edilio. Quinn. I have made a lot of mistakes. And maybe I’m making one now, too. But I’m tired of avoiding a fight. And I’m tired of trying to run away. I’m very, very worried I’m going to get you all killed. So you guys all have to decide for yourselves whether you want to go with me. But I have to go back to Perdido Beach.”

“We’re going to fight Caine?” Quinn asked in alarm.

“About time,” Edilio said.

“Welcome to McDonald’s,” Albert said. “How may I help you?”

“Hey, Albert,” Mary said. She looked up at the menu, which had a number of items covered over with taped-on black construction paper. Salads had disappeared quickly. Milk shakes were gone because the machine had broken down.